In many fields, of which a few have been mentioned above as examples, it is normally necessary to transfer fluids from one process unit, such as a vessel or bag of a conventional type or of a now more common disposable type, to another or to other equipment without these fluids risking to be contaminated with foreign particles, especially airborne bacteria and the like or gaseous air pollutants. In the fields above, there is, inter alia, a more or less continuous need for sampling of fluids, for instance for microbiological control, cell counting or various chemical analyses, or supply of regulating or active substances, for instance a pH buffer or a biological starter culture, in certain process steps in the manufacture of products in the respective fields. Whenever a new connection for the purposes above has to be made to transfer fluids from one vessel to another, there is a great risk of contamination of the fluids, especially in non-sterile spaces.
Such connection can occur by introducing a sterile needle connected to one vessel via a tube or pipe, into a sterile membrane connected to the other vessel. In the interconnection, the connecting components and/or the fluids are exposed to the risk of being contaminated with airborne bacteria, spores etc. and by incorrect handling of the connecting components.
To reduce the risk of contamination when interconnecting two or more vessels for transfer of fluids between them, instead of the above-described needle connecting device, a sterile connector has been suggested, inter alia, by U.S. Pat. No. 3,909,910, with a device for sealing between two interconnectable connecting means included in the sterile connector, with opposing openings to allow, when interconnected, transfer of a fluid between them. The device has sealing elements, which are arranged on the connecting means around the openings and are provided with protective films covering the sealing elements and the openings and being removable in the final interconnection. With the connecting means arranged end-to-end with the openings opposite each other, and with the sealing elements pressed against each other during elastic deformation, the protective films engaging each other are manually pulled off at the same time from the connecting means.
When pulling off the protective films, they are folded back on themselves, and even if they are very thin there arises in the folding area a small gap with a width corresponding to the width of the protective films. This gap “moves” in the pull-off direction and passes the area of the openings in the sealing elements and the connecting means, so that airborne contamination is entrained by the gap and risks entering the openings and contaminating the fluid.